error 0
 ==24677== Memcheck, a memory error detector
 ==24677== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
 ==24677== Using Valgrind-3.15.0.GIT and LibVEX; rerun with -h for copyright info
 ==24677== Command: ./try
 ==24677==
 Alarm clock
 ==24677==
 ==24677== Process terminating with default action of signal 15 (SIGTERM)
 ==24677==    at 0x4039D0: merge (controlbits.c:94)
 ==24677==    by 0x40399F: merge (controlbits.c:91)
 ==24677==    by 0x4039B0: merge (controlbits.c:92)
 ==24677==    by 0x403932: sort (controlbits.c:118)
 ==24677==    by 0x403924: sort (controlbits.c:117)
 ==24677==    by 0x403932: sort (controlbits.c:118)
 ==24677==    by 0x403924: sort (controlbits.c:117)
 ==24677==    by 0x40382E: composeinv (controlbits.c:141)
 ==24677==    by 0x403325: controlbitsfrompermutation (controlbits.c:197)
 ==24677==    by 0x403709: controlbitsfrompermutation (controlbits.c:242)
 ==24677==    by 0x403709: controlbitsfrompermutation (controlbits.c:242)
 ==24677==    by 0x4031D0: controlbits (controlbits.c:255)